HD Broadcasting

Seven finally launched their main channel in High Definition here in Darwin, took them a couple of years. Does it apply to all Southern Cross Seven broadcasting areas?

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Definitely no upgrade for Central. I havenā€™t heard anything here about Spencer Gulf/Broken Hill.

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Hard to believe so many parts of OZ didnā€™t have Seven in HD.

TV-NT have they dumped the SD version of 7 there as well, like they have in regional Queensland?

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Doesnā€™t look like it.

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Most regional WA, and Remote and Central sites build the mux as each site as they are fed from VAST. (The remainder are fed off-air from a nearby VAST fed site). Due to the nature of VAST, it transmits all of the channels in whatever configuration the satellite service requires, so canā€™t transmit a pre-build MUX, requiring each site to build a MUX itself. The distances between sites also make it impossible to have a main site with all other sites being fed off-air as is possible in the eastern states.

For all other areas, the MUX is built in the playout centre and sent to the main transmitter sites, with additional repeater sites being fed off-air.

How the stream is sent to the transmitter varies. WIN and Prime send use the Digital Distribution Australia (DDA - owned by WIN) network of point-to-point wireless links for most of their sites. SCA use fixed line (most likely still the Telstra DVN) to their local offices/studios and then use a wireless point-to-point link for the last ā€œmileā€ to the transmitter site.
The metros, being larger markets with just one main site, as youā€™ve stated have more complicated backup paths with more duplication of equipment.

So they didnā€™t need to upgrade/replace/purchase any equipment. Plus, using MPEG-2 for HD also gives greater access as almost all TVā€™s currently in operation would be HD compatible for MPEG-2, but far less are MPEG-4 compatible.

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Aha! And thereā€™s why. 7HD in Darwin is in MPEG4 not MPEG2, unlike Queensland.

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I just noticed on my TV that 7HD in Regional QLD is actually 1440x1080 as mentioned above.
Hereā€™s the signal info from my TV

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To me, 1440 isnā€™t really HD.

Itā€™s Donald Trump like ā€œfakeā€ HD

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How is it that a 1440x1080 footage can be shown in 16:9, from my calculations 1440x1080 should be 4:3 ?

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SD is 720x576. Your TV is meant to see the ā€˜16:9 flagā€™ and stretch it to fit. From memory SBS HD MPEG-2 was 1440 and there was another network that did it too. Maybe WINā€™s GEM?

Itā€™s weird how 7 Qld is experiencing issues with this. WIN had similar problems when they converted 9Gem to SD. I canā€™t work out why it takes so long to rectify. Perhaps squeezing bandwidth results in some automatic correction which causes it.

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Very interestingā€¦ seems like a dodgy way to broadcast a video signal, to expect the device receiving the signal to stretch it out.

Yeah, very weird. Given that 720x576 is the default for SD, is it possible that 7 QLD simply arenā€™t broadcasting any aspect ratio information with their signal, resulting in 7food Network coming through as 4:3?

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Very possible. Just not sure of the reason. Like I said, it must be something they can only rectify by testing and tinkering over time. Suggests to me itā€™s bandwidth related or related to the balance of MPEG-2 and MPEG-4 services in one mux. Hopefully someone here can shed some light on it?

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I was under the impression that - at least on DVB-T - all of the MPEG-2 HD signals had broadcast in 1440x1080i

Maybe in the beginning they did? Itā€™s definitely a standard, but I remember people commenting on various forums that it was unusual that SBS was doing it.

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SBS experimented with 1280x1080 for a brief period after switching from 720p, that caused a lot of receiver issues so they moved to the more standard 1440x1080 until they went MPEG4. The ABC also briefly - I think like a day or two - tried 960x720p on News 24, again lots of receivers didnā€™t like that.

Pretty much every network ran with 1440x1080 on their MPEG2 HD services, some changed that just prior to HD multichanneling to run at the full 1920x1080, but then I believe most if not all then changed back after launching SD multichannels to offset the bitrate cut that involved.

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I recall there was an interesting reason for their switch from 720p to 1080i. Something to do with the technical challenges internally with running both an interlaced 576i and progressive 720p service in simulcast. Switching to 2 interlaced services was the outcome 576i/1080i. Might have also had something to do with the subtitles they run on foreign language programs too I recall.

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Sunrise on 7HD in Central Qld didnā€™t look as good as Studio 10 on WIN HD . Studio 10 was very bright, sharp and clear, Sunrise was bright but not sharp (if that makes sense?). Perhaps there is no difference ? It does look better on WIN HD though.

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With 7HD in Regional QLD being MPEG 2, it will struggle for clarity against the more efficient MPEG 4 that WIN are using.

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Next year will 7 HD Regional QLD be changing to MPEG-4 ? Is only WIN using MPEG-4 and not 7 ,9 and 10 in metro areas?

All other main channel HD services such as 9HD, SBSHD Viceland HD, ABCHD, 7HD are in MPEG4 metro and regional.

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